Before the balancing on dps class I wanted to post my take on the game surrounding the melee dps for single target (ST) partys on order side. This might touch on the WB aspect of certain class but will mainly focus around ST so please don't bring this to the blob topic

I'm talking here of 6 mens squad facing good opposition, your personnal exp in 1v1's are irrelevent here (sorry :p).
After the recent patch and the nerf to double SL DW comp wich was the best comp for SC's Mdps we can start talking about true single target (ST) comp.
I am a Order main (but not prider, I also play destro), and played a lot of different dps class on order.
I'll overview bellow each Melee dps (Mdps) class with what they bring regarding CC's, Utility, DPS, weakness.
The class and spec i'll be covering are : White Lions (WL), Assault Shadow Warriors (ASW), 2Handers Slayers (2hSL), Witch Hunters (WH) and Wrath Warrior Priest (WWP).
White Lions:
Hard CC's : M1 unbreakable range root (Incredibly powerfull VS range and healers since they don't have a breafree ability), Knock Down (KD) [Spec], Silence [Spec], Fetch. Total of 4 = S TIER
Utility : Armor Debuff (best one on Order side, without requirement), Interupt, Outgoing Healdebuff (all those abilitys are in the tree spec so you gotta chose since you can't get them all). Jump, its really hard to get away from a WL, creating space between them and you is almost impossible, and he can gap close or switch target very easyly.A++ TIER , just missing that key tool, incoming healdebuff on demand.
DPS : Due to all the CC's, the extra utility from mobility armor debuff, pet harassing you from distance and possibly the execute ability + 2hander with bloodlord weapon, the class is very bursty, stays on the target and drop massiv damage : S TIER
Weakness: Don't bring an incoming heal debuff (can slot the fort weapon if there is no better option but still), Playing with a "buggy" pet that get focus. The WL must be playing with some tactic around the pet wich can be frustrating.
Side note: The only way to counter a WL is to kill the pet, lots of damage & CC's comes from it. If the pet isnt getting killed constantly a good white lion will do massiv work for his squad. Therefor the pet can't be to tanky wich stop WL from using it in WB and don't allow order to have ST pulls in WB.
General : S TIER , this is a must in every ST comp. Any comp would underperform compare to one with a WL.
Assault Shadow Warriors:
Hard CC's: KD's (1 melee from spec + 1 mid range [65 feet] if vengefull), Disarm.
Bringing strong CC's with a mid range KD to help gap close for your squad S TIER
Utility : 10% increase chance to crit for your squad on a target, range snare, very powerfull heald debuff (no CD but req ailing on target). Has a gap closer (45 feet like white lion but 20 sec CD [10 sec for white lions, wich is base lane on the class]), AP buff for the party. Overall brings very good utility to the squad helping a lot the other dps of the squad and the tank to get to the target : S TIER
Damage : The ASW isnt the most bursty class but can still harass an oppenant from distance, isnt the most bursty of the Mdps. A TIER
Weakness : Dont have a Charge and a breakfree abilitie, it has a backflip to help him create space underpressure but the ability can get parryed and wont work then. No aoe detaunt. Balance that with strong defensiv tools and high avoidance. Could use Shadowstep to get away but then will waste the only gap closer it has.
General : One of the best at assisting and helping his squad to gap close and kill a target, true team player

2 hand Slayers:
Hard CC's: KD (undefendable but release the rage), does'nt bring much in regard of CC's B Tier
Utility: Spellbreaker, unique ability very strong main damage ability with great utility for killing the target, heal debuff, party buff (AP). If played with short temper, and full red low CD on KD and healdbuff. A TIER
Damage: If the SL gets to his target (might need help from his teammates), he will drop massiv burst damage with bloodlord 2h & spellbreaker. Don't let him touch you of you will suffer S TIER .
Weakness: The class needs a team helping him getting onto the targets, no gap closer, just has charge has escape and catch up tools. You pretty much have to play it full red so your squishy, be carefull.
General : Very dependant on the team around him, low CC, ok utility great damage : A TIER
Wich Hunters :
Hard CC's: Silence, Disarm, KD's (from spec Dragon gun [short range 30 feet] and pistol wip [from behind]. Brings decent CC's to the squad, can engage invis securing a key KD. Compare to ASW just behind it, with a shorter range KD and a positional requirement for the other one (can hardly get both KD's since they are both speced one. A++ TIER
Utility: Double healdebuff is an option (outgoing and incoming). Can bring a big toughness debuff (Exitwounds), init debuff (increas crit), sort of a decent armor debuff has engage from stealth. STAKE, unique abilities stoping an enemy from getting rezed very big on killing key target. S TIER .
Damage: Isnt the most bursty class, BaL can do massiv damage but isnt my fav finisher, its readable by the enemy squad, neeed a long time before droping the big damage (building your accusations + 9 sec dots before final big tic). more of a constant damage in the squad. A TIER
Weakness: low mobility and fragile ( can spec into full parry and full disrupt). Punt and snare him and this will reduce the pressure.
General : Like ASW this class in 6mens is a true teamplayer bringing great and unique utility, been abble to double healdebuff a target and STAKE A++ TIER
Wrath Warrior Priest :
Hard CC's: Silence ... kinda of a jk to have only 1 hard cc that isnt a lockdown on a target C TIER
Utility: Incoming heal debuff, init debuff, damage aura. Great support healing with lifetap for ST heal, or party heal, dispel, and rez. Can slot utility moral for assisting heal and help prevent massiv drop of damage from the enemy, can bring Wounds buff if no heal WP. Overall good utility, sort of unique with it been heavy focus around the heal (but you kind of have healers for that ...) A TIER
Damage: If on the target with a team helping him can drop good damage, with a good execute, a decent self buff. A++ TIER[/b]
Weakness: Mobility, no charge, no gap closer, no hard lockdown on target. Can struggle sticking to the target. Need a team build around him.
General: the class has clear weekness and just far less tools than any other Mdps A TIER.
Side note: To the people sayin "Don't play Wrath, roll a true dps class". If the spec exist you should be abble to play it

Conclusion:
I think that every class can be played and find succes in 6 mens, so they are all VIABLE, but they are not all competitiv.
It is clear that One class is way above any other class in the regard of 6 mens Mdps squad and that is WL. They bring to many unique things and are getting balanced around not having an incoming healdebuff and a squishy/buggy pet.
If you wanna build your squad you can lock 1 dps slot for WL regardless of the rest of the team ...
Changes:
WL: Sorry buddy's but you guys need a nerf and to give some of your lovely tools to the other class in order, or just not been the only one bringing certain things ...
CC's: Completly remove Fetch from WL and give it to an other class (BOMB DROPPED). This will open up ST pull in WB for order since it wont be tied to a pet anymore, and might bring an other class into order WB ...
Utility: WL cant be the only Mdps with an on demand armor debuff, making every comp without a WL needing a IB ...
Damage: Reduce some numbers ...
ASW:
Buff: remove the parry aspect of the backflip. And give a speed boost after the Shadowstep, with lags and **** using it to see yourself 15feet away when landing is kinda terrible ... Don't need much more, already an A++ tier class in what they do great overall just a bit of love regarding a clear weakness.
WH:
Buff: CC's and utility are great, damage can feel underwelming, adjust some numbers. Like ASW already a very good class, very geared dependant... maybe some love to PvE gear so a WH can do some decent work before been full BiS would be great for our friends with the best lookings hats !
2hSL:
Buff: Rework the spec tree, the Wounds debuff is nice if no KOTBS but get outshined by the KOTBS one ... and a DoT in a very bursty style of play is kinda meeeh (good damage but, once again just damage ...). The channel from left tree is unused and could be nice to see it in the middle tree (1st ability with req of having a 2h). Eather way give them a gap closer with a requirement of 2h or the fetch from WL has second abilities. Having a usefull tactic from the midtree could be great aw ... (increase crit damage +25% like chopa base race one ?).
WWP:
Give them a charge and a KD with req of having a 2h equip (like breakfree). Remove the buff that gives you -5sec and 25% armor pen, give them the same armor debuff than WL.
Removing that buff means 0 AOE capability in the current stat of the WWP, so some love need to be given to them in that regard. We could imagine a Hack and Slash (WL tactic) but for WP, a channel ability and change to the Smite (no CD if wielding a 2h).
That's it for me, thanks for reading
Vbax